Standing
Strong
Engineer advocates home designs that protect
against wind and water
L
ast fall, as remnants of Hurricane Noel
barreled north toward New York and
New England with winds approaching
80 miles per hour, NJIT faculty member Rima Taher sat riveted to her television screen. As Noel brutalized homes
and terrain, she witnessed the vast damage that can
be caused by storms packing less than the punch
of a full-blown hurricane. A civil engineer who researches, writes and teaches about the best ways for
anyone — especially architects — to contend with
nature’s most destructive elements, she did not take
the drama lightly.
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“Design of Low-Rise Buildings for Extreme
Wind Events” by Taher, published in the
March 2007 Journal of Architectural Engineering, highlights recent findings in this area. As
Taher reports, investigators at the Center for
Building Science and Technology (CSTB) in
Nantes, France, performed extensive wind research and tested reduced-scale home models at their sophisticated wind-tunnel facility.
The CSTB researchers ultimately developed
a “cyclonic” or hurricane-resistant dwelling
design. Taher participated in this research
Safer Schools,
Faster Evacuation
Three NJSOA-educated architects
formed the core of a Jacobs Engineering Group Inc. design team that won
Honorable Mention in the 2008 Millennium School International Design
Competition, based in the Philippines.
The team, which placed fourth in the
competition, included Brian D. B.
Novello, a third-year student and intern
at Jacobs’ office in Morristown, New
Jersey, Muhammad H. Hussain ’02 ,
an architectural designer based in
the company’s Houston office, and
Benjamin P. Bakas ’03, an architectural
designer in the Morristown office. The
goal of the competition is to spur the
design of disaster-resistant schools
for developing countries that are prone
to hurricanes, typhoons, floods, earthquakes and other natural disasters.
Photo: Kai Chan
Wicked weather
“All I could think was ‘Watch out!’,” says Taher,
a university lecturer at New Jersey School of
Architecture (NJSOA). “Hurricanes and gale
force storms can be wicked, no matter where
someone lives, and it’s a good idea for everyone to respect them. Just because you live in
the Northeast and not on the Gulf of Mexico,
don’t think you are safe. Nor’easter storms
can be wicked too. They can strike North
Atlantic coasts with near-hurricane winds,
threatening lives and property as horrifically
Rima Taher
as storms in Gulf waters.” Further, as Taher
cautions, many experts project that climate
change will spawn increasingly severe storms
in all parts of the world.
Taher drives home such lessons daily at
NJSOA as she teaches future architects what
they must know to pass licensing examinations and build better, stronger homes. The
author of a new book about structural systems focused on helping architects prepare
for licensing exams, Taher adds her expertise
to that of other NJIT faculty and alumni who
are working to keep people safe when storms
and other natural disasters strike. (See sidebar, “Safer Schools, Faster Evacuation.”)
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and worked on the structural aspect of the
cyclonic design to improve resistance to wind
pressures as well the forces from flood-driven
waters that often accompany hurricanes.
Taher’s journal paper details structural
guidelines and recommendations for the design and construction of hurricane-resistant
homes based on the CSTB findings and other
research. Related reports are also available at
the NJSOA library.
Testing wind effects on structures using wind
tunnels originated in the early 1960s, with the
Boundary Layer Wind Tunnel Laboratory at
the University of Western Ontario, Canada, being a pioneer. Taher also cites related research
conducted by other organizations, such as:
At NJIT, transportation researchers
have developed an evacuation plan
for Cape May County, New Jersey, in
the event of a major hurricane threat.
The study determined how much time
would be required to evacuate the
county, as well as the effectiveness of
the existing lane-reversal plan on New
Jersey’s 47/347 highway corridor. The
researchers proposed improved traffic
evacuation plans, based on results
which indicate that extending the current lane-reversal plan further south
could dramatically reduce the time
required to evacuate the county.
the Wind Engineering Research Center at Texas Tech University, the Wind Engineering Research Center of Tokyo Polytechnic University,
the Wind Engineering and Fluid Laboratory
at Colorado State University, the Natural Hazards Modeling Laboratory at the University of
Notre Dame, and the Wind Simulation and
Testing Laboratory at Iowa State University.
“Hurricanes and gale force storms
can be wicked, no matter where
someone lives, and it’s a good idea
for everyone to respect them.”
Taking architectural action
Taher received a doctorate of civil engineering in building science and technology with
honors in 1986 from the Ecole Nationale des
Ponts et Chaussées, as well as a master’s in the
same discipline. She has a bachelor’s in civil
engineering and urban planning from the
Institut National des Sciences Appliquées de
Lyon. Closer to home, NJIT students regard
the trail-blazing engineer as one of the best.
In 1999 she received NJIT’s Teaching Excellence Award in the category of Instruction by
a Special Lecturer.
Another special forte for Taher is helping to
educate the public. For example, in response
to NJIT publicity about her expertise, U.S.
Senator Robert Menendez sought her participation at a flooding conference organized
by his office in August 2007. The aim of the
conference was to help find solutions to
flooding problems in New Jersey, the state’s
number-one natural hazard.
“Certain home configurations and roof
types can make a big difference,” Taher says
in succinctly summarizing the wealth of research efforts. “Most people don’t realize this,
but design and construction practices could
be modified, and certain aerodynamic features could be incorporated into residential
and commercial construction relatively easily and economically. It is critical for people
in storm-prone regions to know that there
are better design practices and construction
methods as well as materials that can significantly reduce wind forces and, consequently,
damage from extreme wind events.” (See sidebar, “Top Storm Design Tips.”)
Taher looks forward to helping to translate these concepts into structural reality. She
invites builders and developers interested
in prototype construction to contact her at
NJIT, and to learn more about how they can
promote building designs that provide greater
shelter from the forces of nature. n
Author: Sheryl Weinstein is public relations
director at NJIT.
Top Storm Design Tips
Following are examples of design
features that can significantly increase
storm resistance:
n A square floor plan — or better, a
hexagonal or octagonal plan — with a roof
that has four or more panels (hip roof). A
hip roof with four slopes performs better
under wind forces than a gable roof with
two slopes. Research and testing show
that a roof slope of about 30 degrees
works best.
structural failure is often a progressive
process, with the failure of one structural
element triggering the failure of another,
and leading to a total collapse.
n Aerodynamic features to counter the
higher wind pressures that typically affect
areas on a building such as the roof ridge,
corners and eaves. For example, a central
shaft connecting the structure’s internal
space and the roof ridge, which is the
point of highest depression, significantly
reduces wind pressures on the roof by
balancing internal and external pressures.
n Limiting roof overhangs to
counter wind uplift forces that
could trigger a roof failure.
Roof overhangs should be limited to about 20 to 25 inches.
n Relatively inexpensive features that
can reduce wind stresses at the roof’s
lower edges, such as a notched frieze or
grid installed around the perimeter of the
home at the level of the roof gutters.
Storm-resistant “cyclonic” home design
n Elevating the structure on an open
foundation to reduce the risk of damage
from flooding and storm-driven water. For
best results, piles must be braced and
well anchored in the soil to prevent scour.
n Special attention to all connections,
not just between roof and walls. Wind
forces on a roof tend to be uplift forces,
which is why roofs are often blown off
during an extreme wind event. Connections between the structure and
its foundation as well as between
walls must be strong. Complete
Storm-resistant
connection for
roof framing and
exterior wall
Illustration: Courtesy of FEMA
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